New Nikes Wed Free Midsole, Flyknit Upper

The midsole/outsole unit is exactly as you'll find on the Nike Free 5.0. The upper, however, is a new construction. As with the Flyknit Lunar 1, the knitting is dense in areas where you need support and structure, and more open in key areas to allow breathability--such as on top of the foot where a traditional tongue would be found. There's no heel counter--a firm backing to lock your heel in place--but rather the tight stitching and elastic cuff help the shoe conform to the back of your foot, taking on the shape of your heel.

In some online rumors, it was posited that this removable midsole was to allow an "ultra-minimal" experience. But that's not the case. The midsole foam wasn't glued in place only because doing so would reduce flexibility. (Layers of glue also decrease the cushioning properties of a shoe.) Because the entire shoe cinches up from underfoot, Nike was able to find success without gluing the midsole foam down.

How does the Free Hyperfeel perform? We just received samples for wear testing and will have a complete review in time for our December issue, but did put rubber to road during a lunchtime run on Tuesday. The first sensation: soft. That Lunar foam, while thin, delivers a softer-than-expected ride. If you're looking at the rubber outsole (reminiscent of a Vivobarefoot outsole), you may think it's a firm ride. Not so.

When laced up, the upper fits snugly, though not as conforming to the foot at the Free Flyknit. One knock (from this lone tester) is that the heel collar rides a little too high on the medial (inner) edge. It butted right up against my inner ankle bone. We'll watch feedback from our other wear testers to see if this is an isolated occurrence or a broader issue with the fit.

Another note on fit: Keep the midsole in. While you may look at the shoe and think you can run in it without the insert, the upper felt exceptionally baggy, and that already tall heel collar rode even higher. There are better barely there shoes on the market, if that's what you seek. But if you want a lightweight shoe that is super flexible, features a close-fitting upper, and has surprisingly good cushioning, the Hyperfeel is worth a look.

The Free Hyperfeel will be available September 5.

Note: Neither shoe has been tested in the RW Shoe Lab. We'll have lab-derived height, weight, cushioning, and flexibility measurements later this year, along with real-world feedback from our network of wear testers.